1. Field of the Invention
The present invention relates to an apparatus for manufacturing semiconductor devices, and specifically to a manufacturing apparatus which cures and wire-bonds the samples being manufactured.
2. Prior Art
In the prior art, semiconductor devices are manufactured by a process such as that illustrated in the flow chart of FIG. 6. In particular, an adhesive is dropped at 71 by an adhesive dropping device 70 into the die bonding area of a lead frame. Then a die is bonded at 73 by a die bonder 72 to the area where the adhesive has been dropped. The resulting sample is cured at 75 by a curing oven 74 so that the adhesive is dried, thus fixing the die to the lead frame. Afterward, wire bonding 77 is performed by wire bonder 76.
In such conventional processes, the lead frames are packed into a magazine following the die bonding 73, and a multiple number of such magazines (i.e., a number of magazines corresponding to the capacity of the curing oven 74) are collected and placed inside the curing oven 74, where curing is accomplished by heating. After curing is completed, a worker removes the magazines from the curing oven 74, carries the magazine to the wire bonder 76 and sets the magazine in the loader part of the wire bonder 76. Wire bonding 77 is performed by the wire bonder 76. Alternately, in the case of an in-line system, the lead frames are sent to the wire bonder 76 by a belt conveyor which is open to the atmosphere following the curing 75 of the samples.
In the above described conventional processes, the curing oven 74 and wire bonder 76 are separated from each other. Accordingly, it is necessary to transport the lead frames after the curing. Furthermore, in cases where the lead frames or the leads formed on the lead frames consist of copper materials which easily oxidize, it is necessary to cool the lead frames sufficiently to prevent oxidation following the curing before the lead frames can be removed from the curing oven. In addition to requiring a great deal of time, it is also necessary to use a special curing oven which is equipped with a cooling apparatus. Furthermore, the lead frames are heated and cooled a number of times since they must be heated and cooled when they are cured and again when they are wire bonded. As a result, reliability of the product decreases.
In cases where the lead frames must be stored for a long period of time following curing, it is necessary to take steps to prevent oxidation. In addition, in cases where the lead frames are transported from the curing oven 74 to the wire bonder 76 by a belt conveyor which is open to the atmosphere in an in-line system, oxidation occurs while the lead frames are being transported. Accordingly, it is necessary to transport the lead frames after they have been sufficiently cooled in the curing oven (as described above) or to use lead frames wherein bonding areas have been partially plated beforehand.